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Kuniyuki Iwashima 445e99bdf6 rtnetlink: Fix bad unlock balance in do_setlink().
When validate_linkmsg() fails in do_setlink(), we jump to the errout
label and calls netdev_unlock_ops() even though we have not called
netdev_lock_ops() as reported by syzbot.  [0]

Let's return an error directly in such a case.

[0]
WARNING: bad unlock balance detected!
6.14.0-syzkaller-12504-g8bc251e5d874 #0 Not tainted

syz-executor814/5834 is trying to release lock (&dev_instance_lock_key) at:
[<ffffffff89f41f56>] netdev_unlock include/linux/netdevice.h:2756 [inline]
[<ffffffff89f41f56>] netdev_unlock_ops include/net/netdev_lock.h:48 [inline]
[<ffffffff89f41f56>] do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor814/5834:
 #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4064

stack backtrace:
CPU: 0 UID: 0 PID: 5834 Comm: syz-executor814 Not tainted 6.14.0-syzkaller-12504-g8bc251e5d874 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_unlock_imbalance_bug+0x185/0x1a0 kernel/locking/lockdep.c:5296
 __lock_release kernel/locking/lockdep.c:5535 [inline]
 lock_release+0x1ed/0x3e0 kernel/locking/lockdep.c:5887
 __mutex_unlock_slowpath+0xee/0x800 kernel/locking/mutex.c:907
 netdev_unlock include/linux/netdevice.h:2756 [inline]
 netdev_unlock_ops include/net/netdev_lock.h:48 [inline]
 do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406
 rtnl_group_changelink net/core/rtnetlink.c:3783 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3937 [inline]
 rtnl_newlink+0x1619/0x1fe0 net/core/rtnetlink.c:4065
 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:727
 ____sys_sendmsg+0x523/0x860 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmsg+0x271/0x360 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8427b614a9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff9b59f3a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fff9b59f578 RCX: 00007f8427b614a9
RDX: 0000000000000000 RSI: 0000200000000300 RDI: 0000000000000004
RBP: 00007f8427bd4610 R08: 000000000000000c R09: 00007fff9b59f578
R10: 000000000000001b R11: 0000000000000246 R12: 0000000000000001
R13:

Fixes: 4c975fd700 ("net: hold instance lock during NETDEV_REGISTER/UP")
Reported-by: syzbot+45016fe295243a7882d3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=45016fe295243a7882d3
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250407164229.24414-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08 12:33:22 -07:00
arch Miscellaneous x86 fixes: 2025-04-04 07:12:26 -07:00
block block: don't grab elevator lock during queue initialization 2025-04-03 08:32:03 -06:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation net: hold instance lock during NETDEV_CHANGE 2025-04-07 11:13:39 -07:00
drivers net: libwx: Fix the wrong Rx descriptor field 2025-04-08 13:47:47 +02:00
fs 4 ksmbd SMB3 server fixes, all also for stable 2025-04-03 16:18:06 -07:00
include sctp: detect and prevent references to a freed transport in sendmsg 2025-04-08 11:34:06 +02:00
init ARM and clkdev updates for 6.15-rc1 2025-04-03 12:21:44 -07:00
io_uring io_uring: always do atomic put from iowq 2025-04-03 08:31:57 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel Persistent buffer cleanups and simplifications for v6.15: 2025-04-03 16:09:29 -07:00
lib One bugfix and a couple of small late-arriving updates. 2025-04-03 11:16:57 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm - The 2 patch series "mm: fixes for fallouts from mem_init() cleanup" 2025-04-03 11:10:00 -07:00
net rtnetlink: Fix bad unlock balance in do_setlink(). 2025-04-08 12:33:22 -07:00
rust ARM and clkdev updates for 6.15-rc1 2025-04-03 12:21:44 -07:00
samples tracing fixes for 6.15 2025-04-03 09:52:44 -07:00
scripts ARM and clkdev updates for 6.15-rc1 2025-04-03 12:21:44 -07:00
security mseal sysmap: kernel config and header change 2025-04-01 15:17:14 -07:00
sound sound fixes for 6.15-rc1 2025-04-04 07:05:33 -07:00
tools selftests: tls: check that disconnect does nothing 2025-04-08 11:38:49 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-03-25 14:22:07 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap mailmap: add an entry for Nicolas Schier 2025-04-01 15:20:45 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Makefile [ Merge note: this pull request depends on you having merged 2025-03-24 22:06:11 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.